There was an initial phone screening during which a general "HR" type interview was conducted. Mostly personal questions asking about goals and broad themes during my experience. After that, an on campus interview was scheduled during which I spent an entire day interviewing with various engineers within the department. Each brought a different perspective, often describing their role within the company. The technical questions were not particularly challenging. Mostly it consisted of a material taken from my resume. Being able to explain in detail the bullets on the resume seemed to suffice. There didn't seem to be a lot of preparation in terms of difficult engineering questions that you might see at other companies.